Publications

OBJECTIVE: Chronic limb-threatening ischemia (CLTI), the most severe manifestation of peripheral artery disease (PAD), is associated with high risk of major amputation and mortality. While timely revascularization is a cornerstone of CLTI management, disparities in access to care and outcomes persist across US geographic regions. This study aims to evaluate variations in endovascular revascularization for CLTI, healthcare utilization patterns, and outcomes stratified by US regions to inform how we address these disparities.

METHODS: From 2016 through 2023, all endovascular revascularizations for CLTI among Medicare fee-for-service beneficiaries were included and evaluated by Northeast, South, Midwest, and West regions of the US. Follow-up continued through December 31, 2023, with a median duration of 625 days (maximum 2921 days). The primary outcome was a composite of death or major amputation. Secondary outcomes included major amputation, all-cause mortality, repeat revascularization, change in ambulatory status, and healthcare utilization before and after revascularization. Multivariable Cox proportional hazards regression models were used to adjust for demographic, clinical, and procedural characteristics.

RESULTS: Among 381,173 beneficiaries, the South performed more than half of all revascularizations throughout the study period (52.18%), followed by the West (17.3%), Northeast (16.2%), and the Midwest (13.9%). After adjustment, the Midwest showed the highest risk for the primary outcome (hazard ratio [HR] 1.20, 95% confidence interval [CI]: 1.18, 1.22, p<0.0001) followed by the South (HR 1.11, 95% CI 1.10, 1.13, p<0.0001) and West (HR 1.04, 95% CI 1.02, 1.06, p<0.0001), all compared to the Northeast. Healthcare utilization analyses revealed fewer outpatient visits with a vascular provider before and after revascularization in all regions compared to the Northeast with the lowest rates in the Midwest (before revascularization: adjusted rate ratio [aRR]: 0.73; 95% CI: 0.72, 0.74; p<0.0001; after revascularization: aRR: 0.73; 95% CI: 0.72, 0.74; p<0.0001) CONCLUSIONS: Disparities in access to care and outcomes persist across U.S. regions for Medicare beneficiaries with CLTI and influence healthcare utilization and outcomes. The Midwest region in particular, that care for a high proportion of rural patients, experience the greatest risks of amputation and death related to CLTI, which may in part be due to less frequent healthcare contact following revascularization. Targeted improvements in healthcare access, especially in rural and economically disadvantaged regions, are needed to enhance outcomes in CLTI patients.

Renal denervation has recently emerged as a novel approach to improving blood pressure control, particularly in patients with uncontrolled or resistant hypertension. Although a substantial body of evidence has accumulated regarding the procedure's efficacy and safety, considerable variation exists across studies in the primary measures used to assess treatment response. The degree of response also differs widely among individuals, highlighting the importance of identifying factors associated with enhanced or limited responses to renal denervation. In this review, we summarize the currently available evidence on response parameters and predictors of response to renal denervation and offer perspectives for future research.

Renal denervation (RDN) is an innovative procedure with regulatory approval for treating patients whose blood pressure remains uncontrolled despite lifestyle changes and the prescription of antihypertensive medications. It is important to consider how to create accessible patient referral pathways for this complementary therapy in the context of differing healthcare systems and the availability of appropriate resources. Today, most hypertensive patients are managed by primary care practitioners in the community. This paper considers various program models that integrate RDN into clinical practice, from decentralized systems where community physicians refer patients to an RDN facility, to centralized hypertension or academic centers that provide comprehensive care. Providing community practices with checklists that guide patient selection for possible referral for RDN is an important start to the process. Key to the success of an RDN program at an interventional facility is the careful selection of patients. Ideally, this is managed by a team that includes interventional physicians skilled in the RDN procedure, clinicians knowledgeable about hypertension management who can confirm the suitability of patients referred for the procedure, and supporting nursing staff to guide patients through the process. By adopting the practices outlined in this paper, the availability of RDN can be appropriately applied to improving hypertension control in patients at need, in turn reducing their risk of adverse cardiovascular outcomes.

OBJECTIVE: This first in human study evaluated the six month angiographic and one year clinical outcomes of a novel thin strut, sirolimus eluting, resorbable scaffold for symptomatic below the knee peripheral arterial disease (PAD). RESOLV I is an international, prospective, multicentre, single arm study assessing the performance of the MAGNITUDE drug eluting resorbable scaffold (DRS) for the treatment of below the knee lesions in patients with symptomatic PAD.

METHODS: Angiographic and duplex ultrasound evaluations were performed by independent core labs at baseline, post-DRS implantation, and at six months follow up. Binary re-stenosis (> 50% diameter stenosis) was determined via quantitative vascular angiography or duplex ultrasound when quantitative vascular angiography was unavailable. Peri-operative death, major adverse limb events, and functional status were evaluated up to one year.

RESULTS: Thirty five patients (mean age 74.5 ± 6.0 years) were enrolled: six (17%) had chronic total occlusion lesions and 25 (71%) had a baseline Rutherford-Becker classification of stage 5. The mean lesion length was 30.1 ± 12.0 mm. The binary re-stenosis rate at six months was 10% (3/31) (angiographic patency of 90%) and mean in segment late lumen loss was 0.75 ± 0.74 mm. Improved Rutherford class at 12 months follow up was achieved in 88% (29/33) of patients and most were asymptomatic (Rutherford-Becker class 0). No amputation or clinically driven target lesion revascularisation events were seen through 12 months.

CONCLUSION: Early results of the RESOLV I study showed that implantation of a thin strut MAGNITUDE DRS achieved low binary re-stenosis rates at six months, as well as improvement in functional status, with no clinically driven target lesion revascularisation at one year.

BACKGROUND AND AIMS: Radial access site for percutaneous coronary intervention (PCI) is recommended by clinical practice guidelines because of superior outcomes compared with femoral access site. Historically, the adoption of radial access site in the USA has lagged behind much of the rest of the world, but contemporary data on access site selection across the spectrum of clinical presentations and its association with outcomes are lacking.

METHODS: A retrospective cohort study from the National Cardiovascular Data Registry's CathPCI Registry was conducted including PCIs performed between 1 January 2013 and 30 June 2022. The comparative safety of radial vs femoral access site for PCI was evaluated with instrumental variable analysis, a technique that can be used to support causal inference, exploiting operator variation in access site preferences as the instrumental variable.

RESULTS: Overall, 6 658 479 PCI procedures were performed during the study period, of which 40.4% (n = 2 690 355) were performed via radial access site, increasing from 20.3% in 2013 to 57.5% in 2022. This increase was seen in all geographic regions and across the full spectrum of presentations, with the largest relative increase seen in patients with ST-elevation myocardial infarction. Overall, 2 420 805 PCIs met inclusion criteria for the comparative safety analysis. In instrumental variable analyses, radial access site was associated with lower in-hospital mortality [absolute risk difference (ARD) -.15%, 95% confidence interval (CI) -.20 to -.10], major access site bleeding (ARD -.64%, 95% CI -.68 to -.60), and other major vascular complications (ARD -.21%, 95% CI -.23 to -.18) but a higher risk of ischaemic stroke (ARD .05%, 95% CI .03-.08). There was no association with the falsification endpoint of gastrointestinal or genitourinary bleeding (ARD .00%, 95% CI -.03-.03).

CONCLUSIONS: Over the past decade, use of radial access site for PCI has increased 2.8-fold in the USA and now represents the dominant form of access site across all procedural indications. Based on instrumental variable analyses, PCI with radial access site had lower rates of in-hospital mortality, major access site bleeding, and other major vascular complications compared with femoral access site but a slightly higher risk of ischaemic stroke in contemporary practice.